Polypropylene is used in a variety of materials. In particular, polypropylene has been found useful in forming films and similar materials having a small or reduced thickness. One such material includes slit film tapes, which are used for a variety of applications. Common applications for polypropylene slit film tapes include carpet backing; industrial-type bags, sacks, or wraps; ropes or cordage; artificial grass and geotextiles. They are particularly useful in woven materials or fabrics that require a high degree of durability and toughness. It is beneficial that slit film tapes process easily and are resistant to breakage during all phases of the life of the tape, including manufacturing, weaving, and in the final fabric. Manufacturing of polypropylene slit film tapes is an extrusion process well known in the art, and inferior processability and strength can result in reduced extrusion efficiencies. Slit film tapes that break during weaving result in reduced loom efficiencies as well as a higher level of fabric defects.
Polypropylene slit film tapes are typically prepared from semi-crystalline, propylene homopolymers. These homopolymers are usually isotactic polymers prepared from stereospecific catalysts, such as Ziegler-Natta catalysts, which are well known in the art. Such polymers have provided polypropylene tapes with good properties in the past, however, improvements are needed.